I am debating to put on studs or not to. We average about 16ft of annual snowfall here. Many many steep roads. The town ranges from sea level to about 600ft above sea level. The studs help with traction on steep hills? I will be driving my 2005 WRX. This will be my first full winter here. Many cars here have studs, but many are FWD. Think it will be overkill with snow tires on the WRX?

Winter tires aren't intended to help you go faster. They are intended to help you stop and corner . . . so yes, they are absolutely necessary on an AWD car.

Studs are 1970's technology. They are great on ice, but they suck the rest of the time. You can get a set of ice tires (Toyo Garit KX, Michelin X-ice, Yokohama IG20 etc.) which will perform almost as well on ice and you'll be much happier the rest of the time.

Snow tires work better on snow but aren't as good on ice. They also tend to be less squishy than ice tires. If snow is your main concern you can get Nexen WG321 tires cheap from Walmart. They are a Chinese-made continuation of the discontinued Nokian Hakka 2 tire which is an awesome tire for deep snow. They are studable, so if you decide to get studs that is a great option.